Non-felting wool and methods for preparing the same



. @sistance.

2,980,557 NON-FELTING WOOL METHODS FOR.

PREPARING SAME Kermit S.La Fleur, Union, S.C., and Edwin J. Greene,

Charlotte, N-.C., assignors to Deering Milliken Research Corporation, *Pendleton, S.C., a'corporation of Delaware No Drawing. Filed Jan. 16, 1958, 'Ser. No. 709,199 Claims. (Cl. 117-141) This invention relates to methods for improving the characteristics of wool whichhasfbeen made non-felting by a halogenation procedure and to wool materials prepared by such means.

-It is well known in the art that-fabricsmadefrom wool can be rendered shrink resistant by 'halogenation-of the woolen fibers and wool has been halogenated for this purpose for many years. Thercustomaryprocedure comprises simply immersing .a;wool -fabric into an aqueous solution of a halogenating agent for a period of time suflicient to give a modification'of the epithelial scales of the individual fibers. Unfortunately, however; such aproc- .ess results in chemical degradation ofthe .wool fibers to a measurable extent as :is-evidenced by increased alkali solubility, decreased flex abrasion resistance, and

a harsh hand in the treatedfabrics. V

In the past, many eifortshave been made to eliminate the undesirable effects of "wool 'halogenation and to this end there have been employed a'wide .variety'of halogenating agents includingthe free halogens, organicand inorganic hypohalites, land N-halogenated :organic' compounds such as N-chloroamides, N-chloroimides, and in particular the N-chlorohydantoins. Other. 'isuggestions have included employingzsolvents other thanwatersuch as various ethers or adding to the halogenation vbath various substances such as urea and-other nitrogen compounds. It has further been-suggested that the wool,

while in an acid condition, be halogenated withan-alkaline bath and various" other arrangements'ofp'H :control. :While some of these measures do in fact lessen vto "almaterial extent the amount of undesirable damagewto wool resulting from a halogenationprocedure, even under optimum conditions'there isstill obtained a measurable degradation of the wool fibers as a result .of halogenation.

"It'has now been found that improved "characteristics can be imparted to halogenated woolens by treating the same with a polymerizable material selected .from the group consistingof silicone'compounds and carboxylic acid-metal, Werner type-complexes of-a class,rin each instance, to besubsequentlydefined in greater detail. The

application of only a small percent of one ofthesematerials to woolens in which the scale structure ofthe fibers has been modified by halogenation results in the woolens having an improved 'hand, improved abrasion resistance, and decreased alkali solubility.

The class of woolen materials suitable foruse in this invention includes fabrics composed at leastlargelyof wool'fibers which have had their scale structure so modified by halogenation that the fabrics can suitably be washedby conventional procedures without excessive =felt- .ing shrinkage. In more specific-terms, a fabric suitable for use in the process of 'this invention should have the woolen fibers therein halogenated -tosuch an extent that the fabrics potential area felting-shrinkage is less than about 10%. When woolen fabrics have been halogenated sufliciently to obtain a fabric-characterized by sucha low degree of felting shrinkage, the scale structure of the wool fibers has beenlargely-destroyed and the fabricingherently possesses a stiff boardy hand, a relatively high alkali solubility, and a relatively low abrasion .r'e-

This is generally-true regardless of what I 2,980,557 ICE B t nted Apr.-18,-196-1 ..even under the most advantageous conditions, a riegree of halogenation suflicient to give awool fabric a sat isfactory felting shrinkage for commercial use as. awashable woolen generally results in the fabric having -an alkali solubility at least 10% greater and a flex abrasion :resistance at least 25% less than before zhalogenation. By the procedure of this invention both thefiex abrasion resistance and the alkali solubility-can be restored to-a value at least approaching thatbefore halogenation.

Silicone compoundssuitablefor use in thisinvention include membersof the-class generally referred to as, silicone resins. Thesecompounds are polymers in which silicon atoms are bonded together-by oxygen linkages and can be represented by the following empirical formula:

).0 )t.tti( V wherein R usually representsa methylgr'oup but can representother hydrogen groups'having notrnore than about '6 carbon atoms, a represents anumber ofjfrom about 1.0 to 2.0, b represents a number ofjfrom about 0.25

to 1.25 and a+b is'equal to from about 1.0 to 2.25. Particularly suitable for use inthenew process of this invention are the methylhydrogenpolysiloxane resins which are readily capable of undergoing further polymerization on heating in the presence of a catalyst. The methylhydrogenpolysiloxanes can 'be'represented by the above formula wherein'R is methyl, (1" is equal to 1.0 to 1.5, b equals 0.75 to 1.25 and a+b'is equal to 2.0 to 2.25. Many such compounds are commercially available. v g,

The carboxylic acid metal complexes suitable. for use ,inpthis invention are of the type disclosed, ..for example,

' Patents 2,273,040. 2 62,835., and No. 2,693,458. Such compounds are Werner type com l x of long chain carboxylieacids with ,a tri-valent metallsuch as chromium, al1uninum,'or molybdenum. Complexes of this type are generally available in the form of chlorides and as such are relatively 'stablein aqueous 'or alcoholic solution. Upon dilution of the solution, raising the-pH or by mild heating, the-chloride compound is partially ortotally hydrolyzed to give abasiecomplex which pclymerizes by the formation of metal-oxygenmetal linkages to give an insolublematerial. The-complexes suitable for use in this invention, when in the form of chlorides, can be represented by the formula: RCOgMQgCl OH and the basic complexes before polymerization can suitably be represented by the following empirical formula: RCO Me (OH),, Cl

wherein Me represents metal, R'represents an aliphatic group, and n represents a numberfrom 2 to 4. The metal in these formulas maybe chromium, aluminum, or mo- ,lybdenurn, as previously mentioned, and the aliphatic radical may be any'hydrocarbon, fluorocarbon, or hydrofluorocarbon radical having from about 8 to 20 carbon atoms.

While the exact reason or reasons for the success of the new process of this invention are not fully understood, it would appear that the above described type of polymeric compounds have the unique ability to act as both'plasticizers and anti-swelling agents for wool fibers. The plasticizing of the wool'fibers would-explain the improved hand and improved abrasion resistance particular procedure of halogenation is employed and while. the anti-swelling action would possibly explain the improved alkali solubility ,of the halogenated wool :fibers.

This is only theory, however, and applicants 'do 'not wish 'to'be' limited thereby.

The amount of polymerizable materialthat'sh'ould be applied to the wool will vary somewhat depending upon the particular nature of the material and upon the wool to be treated but as a general rule at least about 0.2% of the polymerizable material should be applied since smaller amounts may not give the desired results, On the other hand, there is generally little advantage in apply ing more than about 4% of the polymerizable material and larger quantities may actually lessen the eifectiveness of the process. about 0.5% to 2%.

The polymerizable material may be applied to the wool fabric in any manner which results in the desired quantity thereof being deposited on the wool fibers. One convenient method of application comprises padding the wool through an aqueous solution or emulsion of such a concentration as to result in there being deposited on the wool the desired quantity of material. A second procedure which is satisfactory in many instances comprises exhausting the polymerizable material onto the wool fabric. In the case of carboxylic acid-chromic complexes, it has been found that halogenated wool is substantive for these materials to a certain extent and if the wetted wool is immersed in an aqueous solution of the complex there can be deposited on the wool, by varying the The preferred range is generally from time of immersion, any desired quantity of the complex;

Exhaustion techniques are, however, more satisfactory when applying silicone materials since these materials are applied from emulsions and all that need be done is to add to the aqueous emulsion a material that is incompatible with the emulsifying agent so that the emulsion wool should be dried at an elevated temperature, for in-. stance, at a temperature of from about 200 F. to 300" F., to result in the curing ofthe polymerizable material.

The invention will now be illustrated by the following specific examples in which all parts are by weight unless otherwise indicated:

EMMPLE I A fabric composed of 87% wool and 13% nylon is carbonized after fulling, scouring, and dyeing. Following dry milling, the fabric is chlorinated in a bath con-V taining 0.5% available chlorine, passed into a coldjantichlor bath containing 1% sodium bisulfite, neutralized with sodium bicarbonate and rinsed. The fabric is then padded through a bath containing 1% of stearatochromic chloride under such conditions as to give a wet pick up of about 100% and is then dried, cured at a temperature of 200 F. to 220 F. for ten minutes, and conditioned overnight before testing.

A fabric sample processed according to the above procedure, as well as chlorinated and unchlorinated control samples were given a total of five 15 minute washes at 140 F. and the area felting shrinkage of each sample was determined after each wash. The results of these tests are given in Table I.

The alkali solubility, abrasion resistance, and hand of a'fabric-processed as aboveand after the fabric had been sheared, sponged, and semi-decated, as well as comparative figures for chlorinated and unchlorinated control samples are given in the following table.

' i i "Table 11 h I Flex Abrasion .Alkali- Resistance Fabric Sample Solubility. Hand r percent Warp Filling p e 19 902 695 Good. inated 22 293 439 Poor-Fair. Chlorinated and treated.-- 19 1,029 887. Excellent.

EXAMPLE II 7 Example] is repeated except that for the stearatochrornic chloride used in the preceding example, there is substituted an equal quantity of a myristic acid-aluminum complex available from 13.1. du PontCompanyunder the name of Du, PontAluminumComplex 101. The

results are substantially the'sam'e. f r

I EXAMPLE III ExampleI is repeated except that an equal amount of a Werner typechromic complex of perfluorocapric 'acid'is substituted for the stearic acid complex employed in Example I. A pronounced improvement in hand, alkali solubility and flex abrasion resistance is obtained.

. EXAMPLE 1v.

'A samp1e of 100% woolen material is prepared for treatment by dry milling in a conventional manner. The woolen material is then divided into three approximately equal portions-and one of the three samples is set aside as'a control.

In'a suitable tank'there is placed 460 gallons of water, ZOO-pounds of ice 'andsuflicient sodium hypochlorite to give an available chlorine concentration of approximately 0.6%. Sulfuric'acid is added to reduce the pHfrom approximately 12.5 to 10 and there is then added 6 gallons of wetting agent (3'gallons eachof'Tergitol EH and Tergitol' #4). A'final check of the solution shows the temperature to be 72 F., a pH of '10, and an available chlorine concentration of 0.64%. Two of the three'sam'ples are then passed continuously through'the chlorination'bath at a linear velocity of 26 yards per min'lite and immediately thereafter are passed through a pairofsqueeze rolls and into a water rinse'which results in the goods being in contact with the chlorinating agent for approximately eight seconds. The samples are then neutralized '"in'-a dolly "washer with sodium bicarbonate solntionfor five minutes, rinsed 15 minutes, extracted anddried' One of the chlorinated samples is padded through'a 1% solution of a stearic acid-chromic complex sold by E. I. du Pont under the name'of (Quilon) to give a pick-up of approximately 100% and is then dried at a temperature of approximately 200 'F. The three samples are then given a totalgof five 15 minute washings at 140 7 F. after which their shrinkage, hand, and abrasion resistance are tested. 7

It is found that chlorination alone gives good 'shrink age control so that even after five washes at 140 F. the felting shrinkage of the chlorinated sample is acceptable. It is found, however, that the plain chlorinated "sample has a thin brittle hand, as compared to "a soft, full, and

is found tohave a hand comparable to the unhalogen'ated mellow hand in the control, the flex abrasion resistance of the chlorinated sample is materially lessened,-the'tensile strength is slightlyldwer, and the alkali solubility is measurably increased. The sample of 'woolen material chlorinated and then treated with the chromic complex control, flex abrasion resistance in excess of the :cpn'trol,

a tensile strength higher than that of the plain chlorinated sample, wrinkle recovery in excess of that of the control and an alkali solubility measurably improved over that of the plain chlorinated sample.

EXAMPLE V A piece of a woolen fabric containing 87% wool and r chlorinated samples is then padded through a 1% solution of a fatty acid-chromic complex (Quilon), to give.

a pick-up of approximately 100%, and "dried at a temperature of approximately 200 F, The second of the chlorinated samples is passed through a bath containing polymer of a member selected from the group consisting of silicones capable of being represented by the formula:

wherein R represents a hydrocarbon radical having not more than about six carbon atoms, number from a is a 1.0 to 2.0, b is a number from 0.25 to 1.25 and a b is equal to 1.0 to 2.25; and carboxylic acidapproximately 1% of an emulsion of a methylhydrogenpolysiloxane resin (Dow Corning No. 1107), a fatty acid salt emulsifying agent and 1% stannous chloride as a catalyst to give a pick-up of approximately 100%.

The sample is then dried .at a temperature of approx-- imately 250 F. 7

All samples were given five 15 minute washes at 140 F. The sample chlorinated without other treatment is found to have an increased alkali solubility, greaty decreasedflex abrasion resistance, and a poor hand. The sample chlorinated and treated with a fatty'acid-chromic complex is found to have an alkali solubility about equal to that of the unchlorinated control and to exceed the control in flex abrasion resistance, hand, and wrinkle recovery. The sample chlorinated and treated with a silicone resin is found to have an alkali solubility only slightly in excess of that of the unchlorinated control, a flex abrasion resistance only slightly less than that of the control and a hand substantially unchanged from that of the control.

EXAMPLE vi A sample of woolen material composed of 60% wool and 40% rayon is divided into two swatches. Swatch number 1 is employed as a control. Swatch number 2 is treated in an aqueous halogenation bath employing 30 parts by weight of bath for each part by weight of wool material. The bath during treatment is held at a temperature of 70-75 F, and initially contains 1% by weight of HCl, 1% sodium chloride, and 0.2% of wetting agent (Tergitol #4), the percentages in each instance being based on solution weight. There is then added to the bath 710% of 1,3-dichloro-5, S-dimethylhydantoin (on weight of wool) and the wool material is passed through the bath vfor 1 hour. The material is then rinsed by overflow for 15 minutes, treated with 5% sodium acetate (on cloth weight) for 15 minutes and then again rinsed by overflow for 15 minutes. The material while still wet is then padded through a 1% solution of a fatty acid-chromic complex (Quilon) and dried. The chlorinated sample has an alkali solubility only slightly in excess of that of the control sample, good flex abrasion resistance, and an excellent hand.

The procedure when employing other polymerizable materials is substantially identical to that illustrated in the above examples. 7

Having thus described our invention, what we desire to claim and secure by Letters Patent is:

1. A washable fabric with an area felting shrinkage of less than 10% which is composed largely of wool fibers having their scale structure destroyed by halogenation to such an extent that they are substantially nonfelting, said fibers having deposited thereon from about 0.2% to 4%, by weight of the wool, of a water-insoluble metal Werner type complexes capable of being represented by the formula:

RCO Me OH Cl.,,

wherein R is a radical selected from the group consisting of hydrocarbon, fluorocarbon, and hydrofluorocarbon radicals having from 8 to 20 carbon atoms, Me represents a metal selected from the group consisting of chromium, aluminum, andmolybdenum, and n is an integer from 2 to 4.

2. A fabric according to claim 1 wherein said polymer is a'methylhydrogenpolysiloxane polymer.

3. A fabric accordingto claim 1 wherein said polymer is a polymer of stearatochromic chloride.

4. A fabric according to claim 1 wherein said polymer is a polymer of myristato aluminum chloride.

5. A fabric according to claim 1 wherein said polymerv is a polymer of perfluorocaprato chromic chloride.

' 6. A method for improving the properties of a fabric formed largely of wool fibers which has been subjected to a degree of halogenation sufficient to reduce its potential felting shrinkage below about 10% and which has a harsh hand, an objectionably high alkali solubility,

. and anundesirably low flex abrasion resistance, which wherein R represent a hydrocarbon radical having not more than about six carbon atoms, a is a number from 1.0 to 2.0, b is a number from 0.25 to 1.25 and a+b is equal to 1.0 to 2.25; and carboxylic acidmetal, Werner type chloride complexes of the formula:

wherein R is a radical selected from the group consisting of hydrocarbon, fluorocarbon, and hydrofluorocarbon radicals having from 8 to 20 carbon atoms, Me represents a metal selected from the group consisting of chromium, aluminum, and molybdenum, and n is an interger from 2 to 4, and basic complexes derived from said chloride complexes by hydrolysis, and thereafter heating said fabric to cure said material to a state such that it is not readliy water dispersible.

7. A method according to claim 6 wherein said material is a methylhydrogenpolysiloxan e polymer.

8. A method according to claim 6 wherein said material is stearato chromic chloride.

9. A method according to claim 6 wherein said material is myristato aluminum chloride.

10. A method according to claim 6 wherein said material is' perfluorocaprato chromic chloride.

References (Iited in the file of this patent UNITED STATES PATENTS 2,599,590 Sookne et al. June 10, 1952 2,702,737 Koons et al. Feb. 22, 1955 2,728,692 Dennett Dec. 27, 1955 2,732,320 Guillissen et al. Jan. 24, 1956 2,774,690 Russell et al. Dec. 18, 1956 2,775,605 Benneville et al. Dec. 25, 1956 2,789,956 Eder Apr. 23, 1957 2,807,601 Dennett Sept. 24, 1957 

1. A WASHABLE FABRIC WITH AN AREA FELTING SHRINKAGE OF LESS THAN 10% WHICH IS COMPOSED LARGELY OF WOOL FIBERS HAVING THEIR SCALE STRUCTURE DESTROYED BY HALOGENATION TO SUCH AN EXTENT THT THEY ARE SUBSTANTIALLY NONFELING, SAID FIBERS HAVING DEPOSITED THEREON FROM ABOUT 0.2% TO 4%, BY WEIGHT OF THE WOOL, OF A WATER-INSOLUBLE POLYMER OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF SILICONES CAPABLE OF BEING EPRESENTED BY THE FORMULA: 